An improved delay-dependent H∞ filtering of linear neutral systems

An improved delay-dependent H_∞ filtering design is proposed for linear, continuous, time-invariant systems with time delay. The resulting filter is of the Luenberger observer type, and it guarantees that the H_∞-norm of the system, relating the exogenous signals to the estimation error, is less than a prescribed level. The filter is based on the application of the descriptor model transformation and Park´s inequality for the bounding of cross terms. The advantage of the new filtering scheme is clearly demonstrated via simple examples.